xref: /openbmc/linux/drivers/tty/serial/imx.c (revision 94c7b6fc)
1 /*
2  *  Driver for Motorola IMX serial ports
3  *
4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5  *
6  *  Author: Sascha Hauer <sascha@saschahauer.de>
7  *  Copyright (C) 2004 Pengutronix
8  *
9  *  Copyright (C) 2009 emlix GmbH
10  *  Author: Fabian Godehardt (added IrDA support for iMX)
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  * [29-Mar-2005] Mike Lee
27  * Added hardware handshake
28  */
29 
30 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
31 #define SUPPORT_SYSRQ
32 #endif
33 
34 #include <linux/module.h>
35 #include <linux/ioport.h>
36 #include <linux/init.h>
37 #include <linux/console.h>
38 #include <linux/sysrq.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44 #include <linux/clk.h>
45 #include <linux/delay.h>
46 #include <linux/rational.h>
47 #include <linux/slab.h>
48 #include <linux/of.h>
49 #include <linux/of_device.h>
50 #include <linux/io.h>
51 #include <linux/dma-mapping.h>
52 
53 #include <asm/irq.h>
54 #include <linux/platform_data/serial-imx.h>
55 #include <linux/platform_data/dma-imx.h>
56 
57 /* Register definitions */
58 #define URXD0 0x0  /* Receiver Register */
59 #define URTX0 0x40 /* Transmitter Register */
60 #define UCR1  0x80 /* Control Register 1 */
61 #define UCR2  0x84 /* Control Register 2 */
62 #define UCR3  0x88 /* Control Register 3 */
63 #define UCR4  0x8c /* Control Register 4 */
64 #define UFCR  0x90 /* FIFO Control Register */
65 #define USR1  0x94 /* Status Register 1 */
66 #define USR2  0x98 /* Status Register 2 */
67 #define UESC  0x9c /* Escape Character Register */
68 #define UTIM  0xa0 /* Escape Timer Register */
69 #define UBIR  0xa4 /* BRM Incremental Register */
70 #define UBMR  0xa8 /* BRM Modulator Register */
71 #define UBRC  0xac /* Baud Rate Count Register */
72 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
73 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
74 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
75 
76 /* UART Control Register Bit Fields.*/
77 #define URXD_CHARRDY	(1<<15)
78 #define URXD_ERR	(1<<14)
79 #define URXD_OVRRUN	(1<<13)
80 #define URXD_FRMERR	(1<<12)
81 #define URXD_BRK	(1<<11)
82 #define URXD_PRERR	(1<<10)
83 #define UCR1_ADEN	(1<<15) /* Auto detect interrupt */
84 #define UCR1_ADBR	(1<<14) /* Auto detect baud rate */
85 #define UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
86 #define UCR1_IDEN	(1<<12) /* Idle condition interrupt */
87 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
88 #define UCR1_RRDYEN	(1<<9)	/* Recv ready interrupt enable */
89 #define UCR1_RDMAEN	(1<<8)	/* Recv ready DMA enable */
90 #define UCR1_IREN	(1<<7)	/* Infrared interface enable */
91 #define UCR1_TXMPTYEN	(1<<6)	/* Transimitter empty interrupt enable */
92 #define UCR1_RTSDEN	(1<<5)	/* RTS delta interrupt enable */
93 #define UCR1_SNDBRK	(1<<4)	/* Send break */
94 #define UCR1_TDMAEN	(1<<3)	/* Transmitter ready DMA enable */
95 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
96 #define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
97 #define UCR1_DOZE	(1<<1)	/* Doze */
98 #define UCR1_UARTEN	(1<<0)	/* UART enabled */
99 #define UCR2_ESCI	(1<<15)	/* Escape seq interrupt enable */
100 #define UCR2_IRTS	(1<<14)	/* Ignore RTS pin */
101 #define UCR2_CTSC	(1<<13)	/* CTS pin control */
102 #define UCR2_CTS	(1<<12)	/* Clear to send */
103 #define UCR2_ESCEN	(1<<11)	/* Escape enable */
104 #define UCR2_PREN	(1<<8)	/* Parity enable */
105 #define UCR2_PROE	(1<<7)	/* Parity odd/even */
106 #define UCR2_STPB	(1<<6)	/* Stop */
107 #define UCR2_WS		(1<<5)	/* Word size */
108 #define UCR2_RTSEN	(1<<4)	/* Request to send interrupt enable */
109 #define UCR2_ATEN	(1<<3)	/* Aging Timer Enable */
110 #define UCR2_TXEN	(1<<2)	/* Transmitter enabled */
111 #define UCR2_RXEN	(1<<1)	/* Receiver enabled */
112 #define UCR2_SRST	(1<<0)	/* SW reset */
113 #define UCR3_DTREN	(1<<13) /* DTR interrupt enable */
114 #define UCR3_PARERREN	(1<<12) /* Parity enable */
115 #define UCR3_FRAERREN	(1<<11) /* Frame error interrupt enable */
116 #define UCR3_DSR	(1<<10) /* Data set ready */
117 #define UCR3_DCD	(1<<9)	/* Data carrier detect */
118 #define UCR3_RI		(1<<8)	/* Ring indicator */
119 #define UCR3_ADNIMP	(1<<7)	/* Autobaud Detection Not Improved */
120 #define UCR3_RXDSEN	(1<<6)	/* Receive status interrupt enable */
121 #define UCR3_AIRINTEN	(1<<5)	/* Async IR wake interrupt enable */
122 #define UCR3_AWAKEN	(1<<4)	/* Async wake interrupt enable */
123 #define IMX21_UCR3_RXDMUXSEL	(1<<2)	/* RXD Muxed Input Select */
124 #define UCR3_INVT	(1<<1)	/* Inverted Infrared transmission */
125 #define UCR3_BPEN	(1<<0)	/* Preset registers enable */
126 #define UCR4_CTSTL_SHF	10	/* CTS trigger level shift */
127 #define UCR4_CTSTL_MASK	0x3F	/* CTS trigger is 6 bits wide */
128 #define UCR4_INVR	(1<<9)	/* Inverted infrared reception */
129 #define UCR4_ENIRI	(1<<8)	/* Serial infrared interrupt enable */
130 #define UCR4_WKEN	(1<<7)	/* Wake interrupt enable */
131 #define UCR4_REF16	(1<<6)	/* Ref freq 16 MHz */
132 #define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
133 #define UCR4_IRSC	(1<<5)	/* IR special case */
134 #define UCR4_TCEN	(1<<3)	/* Transmit complete interrupt enable */
135 #define UCR4_BKEN	(1<<2)	/* Break condition interrupt enable */
136 #define UCR4_OREN	(1<<1)	/* Receiver overrun interrupt enable */
137 #define UCR4_DREN	(1<<0)	/* Recv data ready interrupt enable */
138 #define UFCR_RXTL_SHF	0	/* Receiver trigger level shift */
139 #define UFCR_DCEDTE	(1<<6)	/* DCE/DTE mode select */
140 #define UFCR_RFDIV	(7<<7)	/* Reference freq divider mask */
141 #define UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
142 #define UFCR_TXTL_SHF	10	/* Transmitter trigger level shift */
143 #define USR1_PARITYERR	(1<<15) /* Parity error interrupt flag */
144 #define USR1_RTSS	(1<<14) /* RTS pin status */
145 #define USR1_TRDY	(1<<13) /* Transmitter ready interrupt/dma flag */
146 #define USR1_RTSD	(1<<12) /* RTS delta */
147 #define USR1_ESCF	(1<<11) /* Escape seq interrupt flag */
148 #define USR1_FRAMERR	(1<<10) /* Frame error interrupt flag */
149 #define USR1_RRDY	(1<<9)	 /* Receiver ready interrupt/dma flag */
150 #define USR1_TIMEOUT	(1<<7)	 /* Receive timeout interrupt status */
151 #define USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
152 #define USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
153 #define USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
154 #define USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
155 #define USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
156 #define USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
157 #define USR2_IDLE	 (1<<12) /* Idle condition */
158 #define USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
159 #define USR2_WAKE	 (1<<7)	 /* Wake */
160 #define USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
161 #define USR2_TXDC	 (1<<3)	 /* Transmitter complete */
162 #define USR2_BRCD	 (1<<2)	 /* Break condition */
163 #define USR2_ORE	(1<<1)	 /* Overrun error */
164 #define USR2_RDR	(1<<0)	 /* Recv data ready */
165 #define UTS_FRCPERR	(1<<13) /* Force parity error */
166 #define UTS_LOOP	(1<<12)	 /* Loop tx and rx */
167 #define UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
168 #define UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
169 #define UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
170 #define UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
171 #define UTS_SOFTRST	 (1<<0)	 /* Software reset */
172 
173 /* We've been assigned a range on the "Low-density serial ports" major */
174 #define SERIAL_IMX_MAJOR	207
175 #define MINOR_START		16
176 #define DEV_NAME		"ttymxc"
177 
178 /*
179  * This determines how often we check the modem status signals
180  * for any change.  They generally aren't connected to an IRQ
181  * so we have to poll them.  We also check immediately before
182  * filling the TX fifo incase CTS has been dropped.
183  */
184 #define MCTRL_TIMEOUT	(250*HZ/1000)
185 
186 #define DRIVER_NAME "IMX-uart"
187 
188 #define UART_NR 8
189 
190 /* i.mx21 type uart runs on all i.mx except i.mx1 */
191 enum imx_uart_type {
192 	IMX1_UART,
193 	IMX21_UART,
194 	IMX6Q_UART,
195 };
196 
197 /* device type dependent stuff */
198 struct imx_uart_data {
199 	unsigned uts_reg;
200 	enum imx_uart_type devtype;
201 };
202 
203 struct imx_port {
204 	struct uart_port	port;
205 	struct timer_list	timer;
206 	unsigned int		old_status;
207 	int			txirq, rxirq, rtsirq;
208 	unsigned int		have_rtscts:1;
209 	unsigned int		dte_mode:1;
210 	unsigned int		use_irda:1;
211 	unsigned int		irda_inv_rx:1;
212 	unsigned int		irda_inv_tx:1;
213 	unsigned short		trcv_delay; /* transceiver delay */
214 	struct clk		*clk_ipg;
215 	struct clk		*clk_per;
216 	const struct imx_uart_data *devdata;
217 
218 	/* DMA fields */
219 	unsigned int		dma_is_inited:1;
220 	unsigned int		dma_is_enabled:1;
221 	unsigned int		dma_is_rxing:1;
222 	unsigned int		dma_is_txing:1;
223 	struct dma_chan		*dma_chan_rx, *dma_chan_tx;
224 	struct scatterlist	rx_sgl, tx_sgl[2];
225 	void			*rx_buf;
226 	unsigned int		tx_bytes;
227 	unsigned int		dma_tx_nents;
228 	wait_queue_head_t	dma_wait;
229 };
230 
231 struct imx_port_ucrs {
232 	unsigned int	ucr1;
233 	unsigned int	ucr2;
234 	unsigned int	ucr3;
235 };
236 
237 #ifdef CONFIG_IRDA
238 #define USE_IRDA(sport)	((sport)->use_irda)
239 #else
240 #define USE_IRDA(sport)	(0)
241 #endif
242 
243 static struct imx_uart_data imx_uart_devdata[] = {
244 	[IMX1_UART] = {
245 		.uts_reg = IMX1_UTS,
246 		.devtype = IMX1_UART,
247 	},
248 	[IMX21_UART] = {
249 		.uts_reg = IMX21_UTS,
250 		.devtype = IMX21_UART,
251 	},
252 	[IMX6Q_UART] = {
253 		.uts_reg = IMX21_UTS,
254 		.devtype = IMX6Q_UART,
255 	},
256 };
257 
258 static struct platform_device_id imx_uart_devtype[] = {
259 	{
260 		.name = "imx1-uart",
261 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
262 	}, {
263 		.name = "imx21-uart",
264 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
265 	}, {
266 		.name = "imx6q-uart",
267 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
268 	}, {
269 		/* sentinel */
270 	}
271 };
272 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
273 
274 static struct of_device_id imx_uart_dt_ids[] = {
275 	{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
276 	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
277 	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
278 	{ /* sentinel */ }
279 };
280 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
281 
282 static inline unsigned uts_reg(struct imx_port *sport)
283 {
284 	return sport->devdata->uts_reg;
285 }
286 
287 static inline int is_imx1_uart(struct imx_port *sport)
288 {
289 	return sport->devdata->devtype == IMX1_UART;
290 }
291 
292 static inline int is_imx21_uart(struct imx_port *sport)
293 {
294 	return sport->devdata->devtype == IMX21_UART;
295 }
296 
297 static inline int is_imx6q_uart(struct imx_port *sport)
298 {
299 	return sport->devdata->devtype == IMX6Q_UART;
300 }
301 /*
302  * Save and restore functions for UCR1, UCR2 and UCR3 registers
303  */
304 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
305 static void imx_port_ucrs_save(struct uart_port *port,
306 			       struct imx_port_ucrs *ucr)
307 {
308 	/* save control registers */
309 	ucr->ucr1 = readl(port->membase + UCR1);
310 	ucr->ucr2 = readl(port->membase + UCR2);
311 	ucr->ucr3 = readl(port->membase + UCR3);
312 }
313 
314 static void imx_port_ucrs_restore(struct uart_port *port,
315 				  struct imx_port_ucrs *ucr)
316 {
317 	/* restore control registers */
318 	writel(ucr->ucr1, port->membase + UCR1);
319 	writel(ucr->ucr2, port->membase + UCR2);
320 	writel(ucr->ucr3, port->membase + UCR3);
321 }
322 #endif
323 
324 /*
325  * Handle any change of modem status signal since we were last called.
326  */
327 static void imx_mctrl_check(struct imx_port *sport)
328 {
329 	unsigned int status, changed;
330 
331 	status = sport->port.ops->get_mctrl(&sport->port);
332 	changed = status ^ sport->old_status;
333 
334 	if (changed == 0)
335 		return;
336 
337 	sport->old_status = status;
338 
339 	if (changed & TIOCM_RI)
340 		sport->port.icount.rng++;
341 	if (changed & TIOCM_DSR)
342 		sport->port.icount.dsr++;
343 	if (changed & TIOCM_CAR)
344 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
345 	if (changed & TIOCM_CTS)
346 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
347 
348 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
349 }
350 
351 /*
352  * This is our per-port timeout handler, for checking the
353  * modem status signals.
354  */
355 static void imx_timeout(unsigned long data)
356 {
357 	struct imx_port *sport = (struct imx_port *)data;
358 	unsigned long flags;
359 
360 	if (sport->port.state) {
361 		spin_lock_irqsave(&sport->port.lock, flags);
362 		imx_mctrl_check(sport);
363 		spin_unlock_irqrestore(&sport->port.lock, flags);
364 
365 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
366 	}
367 }
368 
369 /*
370  * interrupts disabled on entry
371  */
372 static void imx_stop_tx(struct uart_port *port)
373 {
374 	struct imx_port *sport = (struct imx_port *)port;
375 	unsigned long temp;
376 
377 	if (USE_IRDA(sport)) {
378 		/* half duplex - wait for end of transmission */
379 		int n = 256;
380 		while ((--n > 0) &&
381 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
382 			udelay(5);
383 			barrier();
384 		}
385 		/*
386 		 * irda transceiver - wait a bit more to avoid
387 		 * cutoff, hardware dependent
388 		 */
389 		udelay(sport->trcv_delay);
390 
391 		/*
392 		 * half duplex - reactivate receive mode,
393 		 * flush receive pipe echo crap
394 		 */
395 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
396 			temp = readl(sport->port.membase + UCR1);
397 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
398 			writel(temp, sport->port.membase + UCR1);
399 
400 			temp = readl(sport->port.membase + UCR4);
401 			temp &= ~(UCR4_TCEN);
402 			writel(temp, sport->port.membase + UCR4);
403 
404 			while (readl(sport->port.membase + URXD0) &
405 			       URXD_CHARRDY)
406 				barrier();
407 
408 			temp = readl(sport->port.membase + UCR1);
409 			temp |= UCR1_RRDYEN;
410 			writel(temp, sport->port.membase + UCR1);
411 
412 			temp = readl(sport->port.membase + UCR4);
413 			temp |= UCR4_DREN;
414 			writel(temp, sport->port.membase + UCR4);
415 		}
416 		return;
417 	}
418 
419 	/*
420 	 * We are maybe in the SMP context, so if the DMA TX thread is running
421 	 * on other cpu, we have to wait for it to finish.
422 	 */
423 	if (sport->dma_is_enabled && sport->dma_is_txing)
424 		return;
425 
426 	temp = readl(sport->port.membase + UCR1);
427 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
428 }
429 
430 /*
431  * interrupts disabled on entry
432  */
433 static void imx_stop_rx(struct uart_port *port)
434 {
435 	struct imx_port *sport = (struct imx_port *)port;
436 	unsigned long temp;
437 
438 	/*
439 	 * We are maybe in the SMP context, so if the DMA TX thread is running
440 	 * on other cpu, we have to wait for it to finish.
441 	 */
442 	if (sport->dma_is_enabled && sport->dma_is_rxing)
443 		return;
444 
445 	temp = readl(sport->port.membase + UCR2);
446 	writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
447 
448 	/* disable the `Receiver Ready Interrrupt` */
449 	temp = readl(sport->port.membase + UCR1);
450 	writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
451 }
452 
453 /*
454  * Set the modem control timer to fire immediately.
455  */
456 static void imx_enable_ms(struct uart_port *port)
457 {
458 	struct imx_port *sport = (struct imx_port *)port;
459 
460 	mod_timer(&sport->timer, jiffies);
461 }
462 
463 static inline void imx_transmit_buffer(struct imx_port *sport)
464 {
465 	struct circ_buf *xmit = &sport->port.state->xmit;
466 
467 	while (!uart_circ_empty(xmit) &&
468 			!(readl(sport->port.membase + uts_reg(sport))
469 				& UTS_TXFULL)) {
470 		/* send xmit->buf[xmit->tail]
471 		 * out the port here */
472 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
473 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
474 		sport->port.icount.tx++;
475 	}
476 
477 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
478 		uart_write_wakeup(&sport->port);
479 
480 	if (uart_circ_empty(xmit))
481 		imx_stop_tx(&sport->port);
482 }
483 
484 static void dma_tx_callback(void *data)
485 {
486 	struct imx_port *sport = data;
487 	struct scatterlist *sgl = &sport->tx_sgl[0];
488 	struct circ_buf *xmit = &sport->port.state->xmit;
489 	unsigned long flags;
490 
491 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
492 
493 	sport->dma_is_txing = 0;
494 
495 	/* update the stat */
496 	spin_lock_irqsave(&sport->port.lock, flags);
497 	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
498 	sport->port.icount.tx += sport->tx_bytes;
499 	spin_unlock_irqrestore(&sport->port.lock, flags);
500 
501 	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
502 
503 	uart_write_wakeup(&sport->port);
504 
505 	if (waitqueue_active(&sport->dma_wait)) {
506 		wake_up(&sport->dma_wait);
507 		dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
508 		return;
509 	}
510 }
511 
512 static void imx_dma_tx(struct imx_port *sport)
513 {
514 	struct circ_buf *xmit = &sport->port.state->xmit;
515 	struct scatterlist *sgl = sport->tx_sgl;
516 	struct dma_async_tx_descriptor *desc;
517 	struct dma_chan	*chan = sport->dma_chan_tx;
518 	struct device *dev = sport->port.dev;
519 	enum dma_status status;
520 	int ret;
521 
522 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
523 	if (DMA_IN_PROGRESS == status)
524 		return;
525 
526 	sport->tx_bytes = uart_circ_chars_pending(xmit);
527 
528 	if (xmit->tail > xmit->head && xmit->head > 0) {
529 		sport->dma_tx_nents = 2;
530 		sg_init_table(sgl, 2);
531 		sg_set_buf(sgl, xmit->buf + xmit->tail,
532 				UART_XMIT_SIZE - xmit->tail);
533 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
534 	} else {
535 		sport->dma_tx_nents = 1;
536 		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
537 	}
538 
539 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
540 	if (ret == 0) {
541 		dev_err(dev, "DMA mapping error for TX.\n");
542 		return;
543 	}
544 	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
545 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
546 	if (!desc) {
547 		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
548 		return;
549 	}
550 	desc->callback = dma_tx_callback;
551 	desc->callback_param = sport;
552 
553 	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
554 			uart_circ_chars_pending(xmit));
555 	/* fire it */
556 	sport->dma_is_txing = 1;
557 	dmaengine_submit(desc);
558 	dma_async_issue_pending(chan);
559 	return;
560 }
561 
562 /*
563  * interrupts disabled on entry
564  */
565 static void imx_start_tx(struct uart_port *port)
566 {
567 	struct imx_port *sport = (struct imx_port *)port;
568 	unsigned long temp;
569 
570 	if (uart_circ_empty(&port->state->xmit))
571 		return;
572 
573 	if (USE_IRDA(sport)) {
574 		/* half duplex in IrDA mode; have to disable receive mode */
575 		temp = readl(sport->port.membase + UCR4);
576 		temp &= ~(UCR4_DREN);
577 		writel(temp, sport->port.membase + UCR4);
578 
579 		temp = readl(sport->port.membase + UCR1);
580 		temp &= ~(UCR1_RRDYEN);
581 		writel(temp, sport->port.membase + UCR1);
582 	}
583 	/* Clear any pending ORE flag before enabling interrupt */
584 	temp = readl(sport->port.membase + USR2);
585 	writel(temp | USR2_ORE, sport->port.membase + USR2);
586 
587 	temp = readl(sport->port.membase + UCR4);
588 	temp |= UCR4_OREN;
589 	writel(temp, sport->port.membase + UCR4);
590 
591 	if (!sport->dma_is_enabled) {
592 		temp = readl(sport->port.membase + UCR1);
593 		writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
594 	}
595 
596 	if (USE_IRDA(sport)) {
597 		temp = readl(sport->port.membase + UCR1);
598 		temp |= UCR1_TRDYEN;
599 		writel(temp, sport->port.membase + UCR1);
600 
601 		temp = readl(sport->port.membase + UCR4);
602 		temp |= UCR4_TCEN;
603 		writel(temp, sport->port.membase + UCR4);
604 	}
605 
606 	if (sport->dma_is_enabled) {
607 		imx_dma_tx(sport);
608 		return;
609 	}
610 
611 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
612 		imx_transmit_buffer(sport);
613 }
614 
615 static irqreturn_t imx_rtsint(int irq, void *dev_id)
616 {
617 	struct imx_port *sport = dev_id;
618 	unsigned int val;
619 	unsigned long flags;
620 
621 	spin_lock_irqsave(&sport->port.lock, flags);
622 
623 	writel(USR1_RTSD, sport->port.membase + USR1);
624 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
625 	uart_handle_cts_change(&sport->port, !!val);
626 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
627 
628 	spin_unlock_irqrestore(&sport->port.lock, flags);
629 	return IRQ_HANDLED;
630 }
631 
632 static irqreturn_t imx_txint(int irq, void *dev_id)
633 {
634 	struct imx_port *sport = dev_id;
635 	struct circ_buf *xmit = &sport->port.state->xmit;
636 	unsigned long flags;
637 
638 	spin_lock_irqsave(&sport->port.lock, flags);
639 	if (sport->port.x_char) {
640 		/* Send next char */
641 		writel(sport->port.x_char, sport->port.membase + URTX0);
642 		goto out;
643 	}
644 
645 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
646 		imx_stop_tx(&sport->port);
647 		goto out;
648 	}
649 
650 	imx_transmit_buffer(sport);
651 
652 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
653 		uart_write_wakeup(&sport->port);
654 
655 out:
656 	spin_unlock_irqrestore(&sport->port.lock, flags);
657 	return IRQ_HANDLED;
658 }
659 
660 static irqreturn_t imx_rxint(int irq, void *dev_id)
661 {
662 	struct imx_port *sport = dev_id;
663 	unsigned int rx, flg, ignored = 0;
664 	struct tty_port *port = &sport->port.state->port;
665 	unsigned long flags, temp;
666 
667 	spin_lock_irqsave(&sport->port.lock, flags);
668 
669 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
670 		flg = TTY_NORMAL;
671 		sport->port.icount.rx++;
672 
673 		rx = readl(sport->port.membase + URXD0);
674 
675 		temp = readl(sport->port.membase + USR2);
676 		if (temp & USR2_BRCD) {
677 			writel(USR2_BRCD, sport->port.membase + USR2);
678 			if (uart_handle_break(&sport->port))
679 				continue;
680 		}
681 
682 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
683 			continue;
684 
685 		if (unlikely(rx & URXD_ERR)) {
686 			if (rx & URXD_BRK)
687 				sport->port.icount.brk++;
688 			else if (rx & URXD_PRERR)
689 				sport->port.icount.parity++;
690 			else if (rx & URXD_FRMERR)
691 				sport->port.icount.frame++;
692 			if (rx & URXD_OVRRUN)
693 				sport->port.icount.overrun++;
694 
695 			if (rx & sport->port.ignore_status_mask) {
696 				if (++ignored > 100)
697 					goto out;
698 				continue;
699 			}
700 
701 			rx &= sport->port.read_status_mask;
702 
703 			if (rx & URXD_BRK)
704 				flg = TTY_BREAK;
705 			else if (rx & URXD_PRERR)
706 				flg = TTY_PARITY;
707 			else if (rx & URXD_FRMERR)
708 				flg = TTY_FRAME;
709 			if (rx & URXD_OVRRUN)
710 				flg = TTY_OVERRUN;
711 
712 #ifdef SUPPORT_SYSRQ
713 			sport->port.sysrq = 0;
714 #endif
715 		}
716 
717 		tty_insert_flip_char(port, rx, flg);
718 	}
719 
720 out:
721 	spin_unlock_irqrestore(&sport->port.lock, flags);
722 	tty_flip_buffer_push(port);
723 	return IRQ_HANDLED;
724 }
725 
726 static int start_rx_dma(struct imx_port *sport);
727 /*
728  * If the RXFIFO is filled with some data, and then we
729  * arise a DMA operation to receive them.
730  */
731 static void imx_dma_rxint(struct imx_port *sport)
732 {
733 	unsigned long temp;
734 
735 	temp = readl(sport->port.membase + USR2);
736 	if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
737 		sport->dma_is_rxing = 1;
738 
739 		/* disable the `Recerver Ready Interrrupt` */
740 		temp = readl(sport->port.membase + UCR1);
741 		temp &= ~(UCR1_RRDYEN);
742 		writel(temp, sport->port.membase + UCR1);
743 
744 		/* tell the DMA to receive the data. */
745 		start_rx_dma(sport);
746 	}
747 }
748 
749 static irqreturn_t imx_int(int irq, void *dev_id)
750 {
751 	struct imx_port *sport = dev_id;
752 	unsigned int sts;
753 	unsigned int sts2;
754 
755 	sts = readl(sport->port.membase + USR1);
756 
757 	if (sts & USR1_RRDY) {
758 		if (sport->dma_is_enabled)
759 			imx_dma_rxint(sport);
760 		else
761 			imx_rxint(irq, dev_id);
762 	}
763 
764 	if (sts & USR1_TRDY &&
765 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
766 		imx_txint(irq, dev_id);
767 
768 	if (sts & USR1_RTSD)
769 		imx_rtsint(irq, dev_id);
770 
771 	if (sts & USR1_AWAKE)
772 		writel(USR1_AWAKE, sport->port.membase + USR1);
773 
774 	sts2 = readl(sport->port.membase + USR2);
775 	if (sts2 & USR2_ORE) {
776 		dev_err(sport->port.dev, "Rx FIFO overrun\n");
777 		sport->port.icount.overrun++;
778 		writel(sts2 | USR2_ORE, sport->port.membase + USR2);
779 	}
780 
781 	return IRQ_HANDLED;
782 }
783 
784 /*
785  * Return TIOCSER_TEMT when transmitter is not busy.
786  */
787 static unsigned int imx_tx_empty(struct uart_port *port)
788 {
789 	struct imx_port *sport = (struct imx_port *)port;
790 	unsigned int ret;
791 
792 	ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
793 
794 	/* If the TX DMA is working, return 0. */
795 	if (sport->dma_is_enabled && sport->dma_is_txing)
796 		ret = 0;
797 
798 	return ret;
799 }
800 
801 /*
802  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
803  */
804 static unsigned int imx_get_mctrl(struct uart_port *port)
805 {
806 	struct imx_port *sport = (struct imx_port *)port;
807 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
808 
809 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
810 		tmp |= TIOCM_CTS;
811 
812 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
813 		tmp |= TIOCM_RTS;
814 
815 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
816 		tmp |= TIOCM_LOOP;
817 
818 	return tmp;
819 }
820 
821 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
822 {
823 	struct imx_port *sport = (struct imx_port *)port;
824 	unsigned long temp;
825 
826 	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
827 
828 	if (mctrl & TIOCM_RTS)
829 		if (!sport->dma_is_enabled)
830 			temp |= UCR2_CTS;
831 
832 	writel(temp, sport->port.membase + UCR2);
833 
834 	temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
835 	if (mctrl & TIOCM_LOOP)
836 		temp |= UTS_LOOP;
837 	writel(temp, sport->port.membase + uts_reg(sport));
838 }
839 
840 /*
841  * Interrupts always disabled.
842  */
843 static void imx_break_ctl(struct uart_port *port, int break_state)
844 {
845 	struct imx_port *sport = (struct imx_port *)port;
846 	unsigned long flags, temp;
847 
848 	spin_lock_irqsave(&sport->port.lock, flags);
849 
850 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
851 
852 	if (break_state != 0)
853 		temp |= UCR1_SNDBRK;
854 
855 	writel(temp, sport->port.membase + UCR1);
856 
857 	spin_unlock_irqrestore(&sport->port.lock, flags);
858 }
859 
860 #define TXTL 2 /* reset default */
861 #define RXTL 1 /* reset default */
862 
863 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
864 {
865 	unsigned int val;
866 
867 	/* set receiver / transmitter trigger level */
868 	val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
869 	val |= TXTL << UFCR_TXTL_SHF | RXTL;
870 	writel(val, sport->port.membase + UFCR);
871 	return 0;
872 }
873 
874 #define RX_BUF_SIZE	(PAGE_SIZE)
875 static void imx_rx_dma_done(struct imx_port *sport)
876 {
877 	unsigned long temp;
878 
879 	/* Enable this interrupt when the RXFIFO is empty. */
880 	temp = readl(sport->port.membase + UCR1);
881 	temp |= UCR1_RRDYEN;
882 	writel(temp, sport->port.membase + UCR1);
883 
884 	sport->dma_is_rxing = 0;
885 
886 	/* Is the shutdown waiting for us? */
887 	if (waitqueue_active(&sport->dma_wait))
888 		wake_up(&sport->dma_wait);
889 }
890 
891 /*
892  * There are three kinds of RX DMA interrupts(such as in the MX6Q):
893  *   [1] the RX DMA buffer is full.
894  *   [2] the Aging timer expires(wait for 8 bytes long)
895  *   [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
896  *
897  * The [2] is trigger when a character was been sitting in the FIFO
898  * meanwhile [3] can wait for 32 bytes long when the RX line is
899  * on IDLE state and RxFIFO is empty.
900  */
901 static void dma_rx_callback(void *data)
902 {
903 	struct imx_port *sport = data;
904 	struct dma_chan	*chan = sport->dma_chan_rx;
905 	struct scatterlist *sgl = &sport->rx_sgl;
906 	struct tty_port *port = &sport->port.state->port;
907 	struct dma_tx_state state;
908 	enum dma_status status;
909 	unsigned int count;
910 
911 	/* unmap it first */
912 	dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
913 
914 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
915 	count = RX_BUF_SIZE - state.residue;
916 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
917 
918 	if (count) {
919 		tty_insert_flip_string(port, sport->rx_buf, count);
920 		tty_flip_buffer_push(port);
921 
922 		start_rx_dma(sport);
923 	} else
924 		imx_rx_dma_done(sport);
925 }
926 
927 static int start_rx_dma(struct imx_port *sport)
928 {
929 	struct scatterlist *sgl = &sport->rx_sgl;
930 	struct dma_chan	*chan = sport->dma_chan_rx;
931 	struct device *dev = sport->port.dev;
932 	struct dma_async_tx_descriptor *desc;
933 	int ret;
934 
935 	sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
936 	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
937 	if (ret == 0) {
938 		dev_err(dev, "DMA mapping error for RX.\n");
939 		return -EINVAL;
940 	}
941 	desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
942 					DMA_PREP_INTERRUPT);
943 	if (!desc) {
944 		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
945 		return -EINVAL;
946 	}
947 	desc->callback = dma_rx_callback;
948 	desc->callback_param = sport;
949 
950 	dev_dbg(dev, "RX: prepare for the DMA.\n");
951 	dmaengine_submit(desc);
952 	dma_async_issue_pending(chan);
953 	return 0;
954 }
955 
956 static void imx_uart_dma_exit(struct imx_port *sport)
957 {
958 	if (sport->dma_chan_rx) {
959 		dma_release_channel(sport->dma_chan_rx);
960 		sport->dma_chan_rx = NULL;
961 
962 		kfree(sport->rx_buf);
963 		sport->rx_buf = NULL;
964 	}
965 
966 	if (sport->dma_chan_tx) {
967 		dma_release_channel(sport->dma_chan_tx);
968 		sport->dma_chan_tx = NULL;
969 	}
970 
971 	sport->dma_is_inited = 0;
972 }
973 
974 static int imx_uart_dma_init(struct imx_port *sport)
975 {
976 	struct dma_slave_config slave_config = {};
977 	struct device *dev = sport->port.dev;
978 	int ret;
979 
980 	/* Prepare for RX : */
981 	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
982 	if (!sport->dma_chan_rx) {
983 		dev_dbg(dev, "cannot get the DMA channel.\n");
984 		ret = -EINVAL;
985 		goto err;
986 	}
987 
988 	slave_config.direction = DMA_DEV_TO_MEM;
989 	slave_config.src_addr = sport->port.mapbase + URXD0;
990 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
991 	slave_config.src_maxburst = RXTL;
992 	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
993 	if (ret) {
994 		dev_err(dev, "error in RX dma configuration.\n");
995 		goto err;
996 	}
997 
998 	sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
999 	if (!sport->rx_buf) {
1000 		dev_err(dev, "cannot alloc DMA buffer.\n");
1001 		ret = -ENOMEM;
1002 		goto err;
1003 	}
1004 
1005 	/* Prepare for TX : */
1006 	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1007 	if (!sport->dma_chan_tx) {
1008 		dev_err(dev, "cannot get the TX DMA channel!\n");
1009 		ret = -EINVAL;
1010 		goto err;
1011 	}
1012 
1013 	slave_config.direction = DMA_MEM_TO_DEV;
1014 	slave_config.dst_addr = sport->port.mapbase + URTX0;
1015 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1016 	slave_config.dst_maxburst = TXTL;
1017 	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1018 	if (ret) {
1019 		dev_err(dev, "error in TX dma configuration.");
1020 		goto err;
1021 	}
1022 
1023 	sport->dma_is_inited = 1;
1024 
1025 	return 0;
1026 err:
1027 	imx_uart_dma_exit(sport);
1028 	return ret;
1029 }
1030 
1031 static void imx_enable_dma(struct imx_port *sport)
1032 {
1033 	unsigned long temp;
1034 
1035 	init_waitqueue_head(&sport->dma_wait);
1036 
1037 	/* set UCR1 */
1038 	temp = readl(sport->port.membase + UCR1);
1039 	temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1040 		/* wait for 32 idle frames for IDDMA interrupt */
1041 		UCR1_ICD_REG(3);
1042 	writel(temp, sport->port.membase + UCR1);
1043 
1044 	/* set UCR4 */
1045 	temp = readl(sport->port.membase + UCR4);
1046 	temp |= UCR4_IDDMAEN;
1047 	writel(temp, sport->port.membase + UCR4);
1048 
1049 	sport->dma_is_enabled = 1;
1050 }
1051 
1052 static void imx_disable_dma(struct imx_port *sport)
1053 {
1054 	unsigned long temp;
1055 
1056 	/* clear UCR1 */
1057 	temp = readl(sport->port.membase + UCR1);
1058 	temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1059 	writel(temp, sport->port.membase + UCR1);
1060 
1061 	/* clear UCR2 */
1062 	temp = readl(sport->port.membase + UCR2);
1063 	temp &= ~(UCR2_CTSC | UCR2_CTS);
1064 	writel(temp, sport->port.membase + UCR2);
1065 
1066 	/* clear UCR4 */
1067 	temp = readl(sport->port.membase + UCR4);
1068 	temp &= ~UCR4_IDDMAEN;
1069 	writel(temp, sport->port.membase + UCR4);
1070 
1071 	sport->dma_is_enabled = 0;
1072 }
1073 
1074 /* half the RX buffer size */
1075 #define CTSTL 16
1076 
1077 static int imx_startup(struct uart_port *port)
1078 {
1079 	struct imx_port *sport = (struct imx_port *)port;
1080 	int retval, i;
1081 	unsigned long flags, temp;
1082 
1083 	retval = clk_prepare_enable(sport->clk_per);
1084 	if (retval)
1085 		goto error_out1;
1086 	retval = clk_prepare_enable(sport->clk_ipg);
1087 	if (retval) {
1088 		clk_disable_unprepare(sport->clk_per);
1089 		goto error_out1;
1090 	}
1091 
1092 	imx_setup_ufcr(sport, 0);
1093 
1094 	/* disable the DREN bit (Data Ready interrupt enable) before
1095 	 * requesting IRQs
1096 	 */
1097 	temp = readl(sport->port.membase + UCR4);
1098 
1099 	if (USE_IRDA(sport))
1100 		temp |= UCR4_IRSC;
1101 
1102 	/* set the trigger level for CTS */
1103 	temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1104 	temp |= CTSTL << UCR4_CTSTL_SHF;
1105 
1106 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1107 
1108 	/* Reset fifo's and state machines */
1109 	i = 100;
1110 
1111 	temp = readl(sport->port.membase + UCR2);
1112 	temp &= ~UCR2_SRST;
1113 	writel(temp, sport->port.membase + UCR2);
1114 
1115 	while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1116 		udelay(1);
1117 
1118 	/*
1119 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1120 	 * chips only have one interrupt.
1121 	 */
1122 	if (sport->txirq > 0) {
1123 		retval = request_irq(sport->rxirq, imx_rxint, 0,
1124 				     dev_name(port->dev), sport);
1125 		if (retval)
1126 			goto error_out1;
1127 
1128 		retval = request_irq(sport->txirq, imx_txint, 0,
1129 				     dev_name(port->dev), sport);
1130 		if (retval)
1131 			goto error_out2;
1132 
1133 		/* do not use RTS IRQ on IrDA */
1134 		if (!USE_IRDA(sport)) {
1135 			retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1136 					     dev_name(port->dev), sport);
1137 			if (retval)
1138 				goto error_out3;
1139 		}
1140 	} else {
1141 		retval = request_irq(sport->port.irq, imx_int, 0,
1142 				     dev_name(port->dev), sport);
1143 		if (retval) {
1144 			free_irq(sport->port.irq, sport);
1145 			goto error_out1;
1146 		}
1147 	}
1148 
1149 	spin_lock_irqsave(&sport->port.lock, flags);
1150 	/*
1151 	 * Finally, clear and enable interrupts
1152 	 */
1153 	writel(USR1_RTSD, sport->port.membase + USR1);
1154 
1155 	temp = readl(sport->port.membase + UCR1);
1156 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1157 
1158 	if (USE_IRDA(sport)) {
1159 		temp |= UCR1_IREN;
1160 		temp &= ~(UCR1_RTSDEN);
1161 	}
1162 
1163 	writel(temp, sport->port.membase + UCR1);
1164 
1165 	temp = readl(sport->port.membase + UCR2);
1166 	temp |= (UCR2_RXEN | UCR2_TXEN);
1167 	if (!sport->have_rtscts)
1168 		temp |= UCR2_IRTS;
1169 	writel(temp, sport->port.membase + UCR2);
1170 
1171 	if (!is_imx1_uart(sport)) {
1172 		temp = readl(sport->port.membase + UCR3);
1173 		temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1174 		writel(temp, sport->port.membase + UCR3);
1175 	}
1176 
1177 	if (USE_IRDA(sport)) {
1178 		temp = readl(sport->port.membase + UCR4);
1179 		if (sport->irda_inv_rx)
1180 			temp |= UCR4_INVR;
1181 		else
1182 			temp &= ~(UCR4_INVR);
1183 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1184 
1185 		temp = readl(sport->port.membase + UCR3);
1186 		if (sport->irda_inv_tx)
1187 			temp |= UCR3_INVT;
1188 		else
1189 			temp &= ~(UCR3_INVT);
1190 		writel(temp, sport->port.membase + UCR3);
1191 	}
1192 
1193 	/*
1194 	 * Enable modem status interrupts
1195 	 */
1196 	imx_enable_ms(&sport->port);
1197 	spin_unlock_irqrestore(&sport->port.lock, flags);
1198 
1199 	if (USE_IRDA(sport)) {
1200 		struct imxuart_platform_data *pdata;
1201 		pdata = dev_get_platdata(sport->port.dev);
1202 		sport->irda_inv_rx = pdata->irda_inv_rx;
1203 		sport->irda_inv_tx = pdata->irda_inv_tx;
1204 		sport->trcv_delay = pdata->transceiver_delay;
1205 		if (pdata->irda_enable)
1206 			pdata->irda_enable(1);
1207 	}
1208 
1209 	return 0;
1210 
1211 error_out3:
1212 	if (sport->txirq)
1213 		free_irq(sport->txirq, sport);
1214 error_out2:
1215 	if (sport->rxirq)
1216 		free_irq(sport->rxirq, sport);
1217 error_out1:
1218 	return retval;
1219 }
1220 
1221 static void imx_shutdown(struct uart_port *port)
1222 {
1223 	struct imx_port *sport = (struct imx_port *)port;
1224 	unsigned long temp;
1225 	unsigned long flags;
1226 
1227 	if (sport->dma_is_enabled) {
1228 		/* We have to wait for the DMA to finish. */
1229 		wait_event(sport->dma_wait,
1230 			!sport->dma_is_rxing && !sport->dma_is_txing);
1231 		imx_stop_rx(port);
1232 		imx_disable_dma(sport);
1233 		imx_uart_dma_exit(sport);
1234 	}
1235 
1236 	spin_lock_irqsave(&sport->port.lock, flags);
1237 	temp = readl(sport->port.membase + UCR2);
1238 	temp &= ~(UCR2_TXEN);
1239 	writel(temp, sport->port.membase + UCR2);
1240 	spin_unlock_irqrestore(&sport->port.lock, flags);
1241 
1242 	if (USE_IRDA(sport)) {
1243 		struct imxuart_platform_data *pdata;
1244 		pdata = dev_get_platdata(sport->port.dev);
1245 		if (pdata->irda_enable)
1246 			pdata->irda_enable(0);
1247 	}
1248 
1249 	/*
1250 	 * Stop our timer.
1251 	 */
1252 	del_timer_sync(&sport->timer);
1253 
1254 	/*
1255 	 * Free the interrupts
1256 	 */
1257 	if (sport->txirq > 0) {
1258 		if (!USE_IRDA(sport))
1259 			free_irq(sport->rtsirq, sport);
1260 		free_irq(sport->txirq, sport);
1261 		free_irq(sport->rxirq, sport);
1262 	} else
1263 		free_irq(sport->port.irq, sport);
1264 
1265 	/*
1266 	 * Disable all interrupts, port and break condition.
1267 	 */
1268 
1269 	spin_lock_irqsave(&sport->port.lock, flags);
1270 	temp = readl(sport->port.membase + UCR1);
1271 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1272 	if (USE_IRDA(sport))
1273 		temp &= ~(UCR1_IREN);
1274 
1275 	writel(temp, sport->port.membase + UCR1);
1276 	spin_unlock_irqrestore(&sport->port.lock, flags);
1277 
1278 	clk_disable_unprepare(sport->clk_per);
1279 	clk_disable_unprepare(sport->clk_ipg);
1280 }
1281 
1282 static void imx_flush_buffer(struct uart_port *port)
1283 {
1284 	struct imx_port *sport = (struct imx_port *)port;
1285 
1286 	if (sport->dma_is_enabled) {
1287 		sport->tx_bytes = 0;
1288 		dmaengine_terminate_all(sport->dma_chan_tx);
1289 	}
1290 }
1291 
1292 static void
1293 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1294 		   struct ktermios *old)
1295 {
1296 	struct imx_port *sport = (struct imx_port *)port;
1297 	unsigned long flags;
1298 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1299 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1300 	unsigned int div, ufcr;
1301 	unsigned long num, denom;
1302 	uint64_t tdiv64;
1303 
1304 	/*
1305 	 * If we don't support modem control lines, don't allow
1306 	 * these to be set.
1307 	 */
1308 	if (0) {
1309 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1310 		termios->c_cflag |= CLOCAL;
1311 	}
1312 
1313 	/*
1314 	 * We only support CS7 and CS8.
1315 	 */
1316 	while ((termios->c_cflag & CSIZE) != CS7 &&
1317 	       (termios->c_cflag & CSIZE) != CS8) {
1318 		termios->c_cflag &= ~CSIZE;
1319 		termios->c_cflag |= old_csize;
1320 		old_csize = CS8;
1321 	}
1322 
1323 	if ((termios->c_cflag & CSIZE) == CS8)
1324 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1325 	else
1326 		ucr2 = UCR2_SRST | UCR2_IRTS;
1327 
1328 	if (termios->c_cflag & CRTSCTS) {
1329 		if (sport->have_rtscts) {
1330 			ucr2 &= ~UCR2_IRTS;
1331 			ucr2 |= UCR2_CTSC;
1332 
1333 			/* Can we enable the DMA support? */
1334 			if (is_imx6q_uart(sport) && !uart_console(port)
1335 				&& !sport->dma_is_inited)
1336 				imx_uart_dma_init(sport);
1337 		} else {
1338 			termios->c_cflag &= ~CRTSCTS;
1339 		}
1340 	}
1341 
1342 	if (termios->c_cflag & CSTOPB)
1343 		ucr2 |= UCR2_STPB;
1344 	if (termios->c_cflag & PARENB) {
1345 		ucr2 |= UCR2_PREN;
1346 		if (termios->c_cflag & PARODD)
1347 			ucr2 |= UCR2_PROE;
1348 	}
1349 
1350 	del_timer_sync(&sport->timer);
1351 
1352 	/*
1353 	 * Ask the core to calculate the divisor for us.
1354 	 */
1355 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1356 	quot = uart_get_divisor(port, baud);
1357 
1358 	spin_lock_irqsave(&sport->port.lock, flags);
1359 
1360 	sport->port.read_status_mask = 0;
1361 	if (termios->c_iflag & INPCK)
1362 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1363 	if (termios->c_iflag & (BRKINT | PARMRK))
1364 		sport->port.read_status_mask |= URXD_BRK;
1365 
1366 	/*
1367 	 * Characters to ignore
1368 	 */
1369 	sport->port.ignore_status_mask = 0;
1370 	if (termios->c_iflag & IGNPAR)
1371 		sport->port.ignore_status_mask |= URXD_PRERR;
1372 	if (termios->c_iflag & IGNBRK) {
1373 		sport->port.ignore_status_mask |= URXD_BRK;
1374 		/*
1375 		 * If we're ignoring parity and break indicators,
1376 		 * ignore overruns too (for real raw support).
1377 		 */
1378 		if (termios->c_iflag & IGNPAR)
1379 			sport->port.ignore_status_mask |= URXD_OVRRUN;
1380 	}
1381 
1382 	/*
1383 	 * Update the per-port timeout.
1384 	 */
1385 	uart_update_timeout(port, termios->c_cflag, baud);
1386 
1387 	/*
1388 	 * disable interrupts and drain transmitter
1389 	 */
1390 	old_ucr1 = readl(sport->port.membase + UCR1);
1391 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1392 			sport->port.membase + UCR1);
1393 
1394 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1395 		barrier();
1396 
1397 	/* then, disable everything */
1398 	old_txrxen = readl(sport->port.membase + UCR2);
1399 	writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1400 			sport->port.membase + UCR2);
1401 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1402 
1403 	if (USE_IRDA(sport)) {
1404 		/*
1405 		 * use maximum available submodule frequency to
1406 		 * avoid missing short pulses due to low sampling rate
1407 		 */
1408 		div = 1;
1409 	} else {
1410 		/* custom-baudrate handling */
1411 		div = sport->port.uartclk / (baud * 16);
1412 		if (baud == 38400 && quot != div)
1413 			baud = sport->port.uartclk / (quot * 16);
1414 
1415 		div = sport->port.uartclk / (baud * 16);
1416 		if (div > 7)
1417 			div = 7;
1418 		if (!div)
1419 			div = 1;
1420 	}
1421 
1422 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1423 		1 << 16, 1 << 16, &num, &denom);
1424 
1425 	tdiv64 = sport->port.uartclk;
1426 	tdiv64 *= num;
1427 	do_div(tdiv64, denom * 16 * div);
1428 	tty_termios_encode_baud_rate(termios,
1429 				(speed_t)tdiv64, (speed_t)tdiv64);
1430 
1431 	num -= 1;
1432 	denom -= 1;
1433 
1434 	ufcr = readl(sport->port.membase + UFCR);
1435 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1436 	if (sport->dte_mode)
1437 		ufcr |= UFCR_DCEDTE;
1438 	writel(ufcr, sport->port.membase + UFCR);
1439 
1440 	writel(num, sport->port.membase + UBIR);
1441 	writel(denom, sport->port.membase + UBMR);
1442 
1443 	if (!is_imx1_uart(sport))
1444 		writel(sport->port.uartclk / div / 1000,
1445 				sport->port.membase + IMX21_ONEMS);
1446 
1447 	writel(old_ucr1, sport->port.membase + UCR1);
1448 
1449 	/* set the parity, stop bits and data size */
1450 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1451 
1452 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1453 		imx_enable_ms(&sport->port);
1454 
1455 	if (sport->dma_is_inited && !sport->dma_is_enabled)
1456 		imx_enable_dma(sport);
1457 	spin_unlock_irqrestore(&sport->port.lock, flags);
1458 }
1459 
1460 static const char *imx_type(struct uart_port *port)
1461 {
1462 	struct imx_port *sport = (struct imx_port *)port;
1463 
1464 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1465 }
1466 
1467 /*
1468  * Configure/autoconfigure the port.
1469  */
1470 static void imx_config_port(struct uart_port *port, int flags)
1471 {
1472 	struct imx_port *sport = (struct imx_port *)port;
1473 
1474 	if (flags & UART_CONFIG_TYPE)
1475 		sport->port.type = PORT_IMX;
1476 }
1477 
1478 /*
1479  * Verify the new serial_struct (for TIOCSSERIAL).
1480  * The only change we allow are to the flags and type, and
1481  * even then only between PORT_IMX and PORT_UNKNOWN
1482  */
1483 static int
1484 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1485 {
1486 	struct imx_port *sport = (struct imx_port *)port;
1487 	int ret = 0;
1488 
1489 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1490 		ret = -EINVAL;
1491 	if (sport->port.irq != ser->irq)
1492 		ret = -EINVAL;
1493 	if (ser->io_type != UPIO_MEM)
1494 		ret = -EINVAL;
1495 	if (sport->port.uartclk / 16 != ser->baud_base)
1496 		ret = -EINVAL;
1497 	if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1498 		ret = -EINVAL;
1499 	if (sport->port.iobase != ser->port)
1500 		ret = -EINVAL;
1501 	if (ser->hub6 != 0)
1502 		ret = -EINVAL;
1503 	return ret;
1504 }
1505 
1506 #if defined(CONFIG_CONSOLE_POLL)
1507 static int imx_poll_get_char(struct uart_port *port)
1508 {
1509 	struct imx_port_ucrs old_ucr;
1510 	unsigned int status;
1511 	unsigned char c;
1512 
1513 	/* save control registers */
1514 	imx_port_ucrs_save(port, &old_ucr);
1515 
1516 	/* disable interrupts */
1517 	writel(UCR1_UARTEN, port->membase + UCR1);
1518 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1519 	       port->membase + UCR2);
1520 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1521 	       port->membase + UCR3);
1522 
1523 	/* poll */
1524 	do {
1525 		status = readl(port->membase + USR2);
1526 	} while (~status & USR2_RDR);
1527 
1528 	/* read */
1529 	c = readl(port->membase + URXD0);
1530 
1531 	/* restore control registers */
1532 	imx_port_ucrs_restore(port, &old_ucr);
1533 
1534 	return c;
1535 }
1536 
1537 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1538 {
1539 	struct imx_port_ucrs old_ucr;
1540 	unsigned int status;
1541 
1542 	/* save control registers */
1543 	imx_port_ucrs_save(port, &old_ucr);
1544 
1545 	/* disable interrupts */
1546 	writel(UCR1_UARTEN, port->membase + UCR1);
1547 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1548 	       port->membase + UCR2);
1549 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1550 	       port->membase + UCR3);
1551 
1552 	/* drain */
1553 	do {
1554 		status = readl(port->membase + USR1);
1555 	} while (~status & USR1_TRDY);
1556 
1557 	/* write */
1558 	writel(c, port->membase + URTX0);
1559 
1560 	/* flush */
1561 	do {
1562 		status = readl(port->membase + USR2);
1563 	} while (~status & USR2_TXDC);
1564 
1565 	/* restore control registers */
1566 	imx_port_ucrs_restore(port, &old_ucr);
1567 }
1568 #endif
1569 
1570 static struct uart_ops imx_pops = {
1571 	.tx_empty	= imx_tx_empty,
1572 	.set_mctrl	= imx_set_mctrl,
1573 	.get_mctrl	= imx_get_mctrl,
1574 	.stop_tx	= imx_stop_tx,
1575 	.start_tx	= imx_start_tx,
1576 	.stop_rx	= imx_stop_rx,
1577 	.enable_ms	= imx_enable_ms,
1578 	.break_ctl	= imx_break_ctl,
1579 	.startup	= imx_startup,
1580 	.shutdown	= imx_shutdown,
1581 	.flush_buffer	= imx_flush_buffer,
1582 	.set_termios	= imx_set_termios,
1583 	.type		= imx_type,
1584 	.config_port	= imx_config_port,
1585 	.verify_port	= imx_verify_port,
1586 #if defined(CONFIG_CONSOLE_POLL)
1587 	.poll_get_char  = imx_poll_get_char,
1588 	.poll_put_char  = imx_poll_put_char,
1589 #endif
1590 };
1591 
1592 static struct imx_port *imx_ports[UART_NR];
1593 
1594 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1595 static void imx_console_putchar(struct uart_port *port, int ch)
1596 {
1597 	struct imx_port *sport = (struct imx_port *)port;
1598 
1599 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1600 		barrier();
1601 
1602 	writel(ch, sport->port.membase + URTX0);
1603 }
1604 
1605 /*
1606  * Interrupts are disabled on entering
1607  */
1608 static void
1609 imx_console_write(struct console *co, const char *s, unsigned int count)
1610 {
1611 	struct imx_port *sport = imx_ports[co->index];
1612 	struct imx_port_ucrs old_ucr;
1613 	unsigned int ucr1;
1614 	unsigned long flags = 0;
1615 	int locked = 1;
1616 	int retval;
1617 
1618 	retval = clk_enable(sport->clk_per);
1619 	if (retval)
1620 		return;
1621 	retval = clk_enable(sport->clk_ipg);
1622 	if (retval) {
1623 		clk_disable(sport->clk_per);
1624 		return;
1625 	}
1626 
1627 	if (sport->port.sysrq)
1628 		locked = 0;
1629 	else if (oops_in_progress)
1630 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1631 	else
1632 		spin_lock_irqsave(&sport->port.lock, flags);
1633 
1634 	/*
1635 	 *	First, save UCR1/2/3 and then disable interrupts
1636 	 */
1637 	imx_port_ucrs_save(&sport->port, &old_ucr);
1638 	ucr1 = old_ucr.ucr1;
1639 
1640 	if (is_imx1_uart(sport))
1641 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1642 	ucr1 |= UCR1_UARTEN;
1643 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1644 
1645 	writel(ucr1, sport->port.membase + UCR1);
1646 
1647 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1648 
1649 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1650 
1651 	/*
1652 	 *	Finally, wait for transmitter to become empty
1653 	 *	and restore UCR1/2/3
1654 	 */
1655 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1656 
1657 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1658 
1659 	if (locked)
1660 		spin_unlock_irqrestore(&sport->port.lock, flags);
1661 
1662 	clk_disable(sport->clk_ipg);
1663 	clk_disable(sport->clk_per);
1664 }
1665 
1666 /*
1667  * If the port was already initialised (eg, by a boot loader),
1668  * try to determine the current setup.
1669  */
1670 static void __init
1671 imx_console_get_options(struct imx_port *sport, int *baud,
1672 			   int *parity, int *bits)
1673 {
1674 
1675 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1676 		/* ok, the port was enabled */
1677 		unsigned int ucr2, ubir, ubmr, uartclk;
1678 		unsigned int baud_raw;
1679 		unsigned int ucfr_rfdiv;
1680 
1681 		ucr2 = readl(sport->port.membase + UCR2);
1682 
1683 		*parity = 'n';
1684 		if (ucr2 & UCR2_PREN) {
1685 			if (ucr2 & UCR2_PROE)
1686 				*parity = 'o';
1687 			else
1688 				*parity = 'e';
1689 		}
1690 
1691 		if (ucr2 & UCR2_WS)
1692 			*bits = 8;
1693 		else
1694 			*bits = 7;
1695 
1696 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1697 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1698 
1699 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1700 		if (ucfr_rfdiv == 6)
1701 			ucfr_rfdiv = 7;
1702 		else
1703 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1704 
1705 		uartclk = clk_get_rate(sport->clk_per);
1706 		uartclk /= ucfr_rfdiv;
1707 
1708 		{	/*
1709 			 * The next code provides exact computation of
1710 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1711 			 * without need of float support or long long division,
1712 			 * which would be required to prevent 32bit arithmetic overflow
1713 			 */
1714 			unsigned int mul = ubir + 1;
1715 			unsigned int div = 16 * (ubmr + 1);
1716 			unsigned int rem = uartclk % div;
1717 
1718 			baud_raw = (uartclk / div) * mul;
1719 			baud_raw += (rem * mul + div / 2) / div;
1720 			*baud = (baud_raw + 50) / 100 * 100;
1721 		}
1722 
1723 		if (*baud != baud_raw)
1724 			pr_info("Console IMX rounded baud rate from %d to %d\n",
1725 				baud_raw, *baud);
1726 	}
1727 }
1728 
1729 static int __init
1730 imx_console_setup(struct console *co, char *options)
1731 {
1732 	struct imx_port *sport;
1733 	int baud = 9600;
1734 	int bits = 8;
1735 	int parity = 'n';
1736 	int flow = 'n';
1737 	int retval;
1738 
1739 	/*
1740 	 * Check whether an invalid uart number has been specified, and
1741 	 * if so, search for the first available port that does have
1742 	 * console support.
1743 	 */
1744 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1745 		co->index = 0;
1746 	sport = imx_ports[co->index];
1747 	if (sport == NULL)
1748 		return -ENODEV;
1749 
1750 	/* For setting the registers, we only need to enable the ipg clock. */
1751 	retval = clk_prepare_enable(sport->clk_ipg);
1752 	if (retval)
1753 		goto error_console;
1754 
1755 	if (options)
1756 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1757 	else
1758 		imx_console_get_options(sport, &baud, &parity, &bits);
1759 
1760 	imx_setup_ufcr(sport, 0);
1761 
1762 	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1763 
1764 	clk_disable(sport->clk_ipg);
1765 	if (retval) {
1766 		clk_unprepare(sport->clk_ipg);
1767 		goto error_console;
1768 	}
1769 
1770 	retval = clk_prepare(sport->clk_per);
1771 	if (retval)
1772 		clk_disable_unprepare(sport->clk_ipg);
1773 
1774 error_console:
1775 	return retval;
1776 }
1777 
1778 static struct uart_driver imx_reg;
1779 static struct console imx_console = {
1780 	.name		= DEV_NAME,
1781 	.write		= imx_console_write,
1782 	.device		= uart_console_device,
1783 	.setup		= imx_console_setup,
1784 	.flags		= CON_PRINTBUFFER,
1785 	.index		= -1,
1786 	.data		= &imx_reg,
1787 };
1788 
1789 #define IMX_CONSOLE	&imx_console
1790 #else
1791 #define IMX_CONSOLE	NULL
1792 #endif
1793 
1794 static struct uart_driver imx_reg = {
1795 	.owner          = THIS_MODULE,
1796 	.driver_name    = DRIVER_NAME,
1797 	.dev_name       = DEV_NAME,
1798 	.major          = SERIAL_IMX_MAJOR,
1799 	.minor          = MINOR_START,
1800 	.nr             = ARRAY_SIZE(imx_ports),
1801 	.cons           = IMX_CONSOLE,
1802 };
1803 
1804 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1805 {
1806 	struct imx_port *sport = platform_get_drvdata(dev);
1807 	unsigned int val;
1808 
1809 	/* enable wakeup from i.MX UART */
1810 	val = readl(sport->port.membase + UCR3);
1811 	val |= UCR3_AWAKEN;
1812 	writel(val, sport->port.membase + UCR3);
1813 
1814 	uart_suspend_port(&imx_reg, &sport->port);
1815 
1816 	return 0;
1817 }
1818 
1819 static int serial_imx_resume(struct platform_device *dev)
1820 {
1821 	struct imx_port *sport = platform_get_drvdata(dev);
1822 	unsigned int val;
1823 
1824 	/* disable wakeup from i.MX UART */
1825 	val = readl(sport->port.membase + UCR3);
1826 	val &= ~UCR3_AWAKEN;
1827 	writel(val, sport->port.membase + UCR3);
1828 
1829 	uart_resume_port(&imx_reg, &sport->port);
1830 
1831 	return 0;
1832 }
1833 
1834 #ifdef CONFIG_OF
1835 /*
1836  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1837  * could successfully get all information from dt or a negative errno.
1838  */
1839 static int serial_imx_probe_dt(struct imx_port *sport,
1840 		struct platform_device *pdev)
1841 {
1842 	struct device_node *np = pdev->dev.of_node;
1843 	const struct of_device_id *of_id =
1844 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1845 	int ret;
1846 
1847 	if (!np)
1848 		/* no device tree device */
1849 		return 1;
1850 
1851 	ret = of_alias_get_id(np, "serial");
1852 	if (ret < 0) {
1853 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1854 		return ret;
1855 	}
1856 	sport->port.line = ret;
1857 
1858 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1859 		sport->have_rtscts = 1;
1860 
1861 	if (of_get_property(np, "fsl,irda-mode", NULL))
1862 		sport->use_irda = 1;
1863 
1864 	if (of_get_property(np, "fsl,dte-mode", NULL))
1865 		sport->dte_mode = 1;
1866 
1867 	sport->devdata = of_id->data;
1868 
1869 	return 0;
1870 }
1871 #else
1872 static inline int serial_imx_probe_dt(struct imx_port *sport,
1873 		struct platform_device *pdev)
1874 {
1875 	return 1;
1876 }
1877 #endif
1878 
1879 static void serial_imx_probe_pdata(struct imx_port *sport,
1880 		struct platform_device *pdev)
1881 {
1882 	struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1883 
1884 	sport->port.line = pdev->id;
1885 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1886 
1887 	if (!pdata)
1888 		return;
1889 
1890 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1891 		sport->have_rtscts = 1;
1892 
1893 	if (pdata->flags & IMXUART_IRDA)
1894 		sport->use_irda = 1;
1895 }
1896 
1897 static int serial_imx_probe(struct platform_device *pdev)
1898 {
1899 	struct imx_port *sport;
1900 	void __iomem *base;
1901 	int ret = 0;
1902 	struct resource *res;
1903 
1904 	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1905 	if (!sport)
1906 		return -ENOMEM;
1907 
1908 	ret = serial_imx_probe_dt(sport, pdev);
1909 	if (ret > 0)
1910 		serial_imx_probe_pdata(sport, pdev);
1911 	else if (ret < 0)
1912 		return ret;
1913 
1914 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1915 	base = devm_ioremap_resource(&pdev->dev, res);
1916 	if (IS_ERR(base))
1917 		return PTR_ERR(base);
1918 
1919 	sport->port.dev = &pdev->dev;
1920 	sport->port.mapbase = res->start;
1921 	sport->port.membase = base;
1922 	sport->port.type = PORT_IMX,
1923 	sport->port.iotype = UPIO_MEM;
1924 	sport->port.irq = platform_get_irq(pdev, 0);
1925 	sport->rxirq = platform_get_irq(pdev, 0);
1926 	sport->txirq = platform_get_irq(pdev, 1);
1927 	sport->rtsirq = platform_get_irq(pdev, 2);
1928 	sport->port.fifosize = 32;
1929 	sport->port.ops = &imx_pops;
1930 	sport->port.flags = UPF_BOOT_AUTOCONF;
1931 	init_timer(&sport->timer);
1932 	sport->timer.function = imx_timeout;
1933 	sport->timer.data     = (unsigned long)sport;
1934 
1935 	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1936 	if (IS_ERR(sport->clk_ipg)) {
1937 		ret = PTR_ERR(sport->clk_ipg);
1938 		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1939 		return ret;
1940 	}
1941 
1942 	sport->clk_per = devm_clk_get(&pdev->dev, "per");
1943 	if (IS_ERR(sport->clk_per)) {
1944 		ret = PTR_ERR(sport->clk_per);
1945 		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1946 		return ret;
1947 	}
1948 
1949 	sport->port.uartclk = clk_get_rate(sport->clk_per);
1950 
1951 	imx_ports[sport->port.line] = sport;
1952 
1953 	platform_set_drvdata(pdev, sport);
1954 
1955 	return uart_add_one_port(&imx_reg, &sport->port);
1956 }
1957 
1958 static int serial_imx_remove(struct platform_device *pdev)
1959 {
1960 	struct imx_port *sport = platform_get_drvdata(pdev);
1961 
1962 	return uart_remove_one_port(&imx_reg, &sport->port);
1963 }
1964 
1965 static struct platform_driver serial_imx_driver = {
1966 	.probe		= serial_imx_probe,
1967 	.remove		= serial_imx_remove,
1968 
1969 	.suspend	= serial_imx_suspend,
1970 	.resume		= serial_imx_resume,
1971 	.id_table	= imx_uart_devtype,
1972 	.driver		= {
1973 		.name	= "imx-uart",
1974 		.owner	= THIS_MODULE,
1975 		.of_match_table = imx_uart_dt_ids,
1976 	},
1977 };
1978 
1979 static int __init imx_serial_init(void)
1980 {
1981 	int ret;
1982 
1983 	pr_info("Serial: IMX driver\n");
1984 
1985 	ret = uart_register_driver(&imx_reg);
1986 	if (ret)
1987 		return ret;
1988 
1989 	ret = platform_driver_register(&serial_imx_driver);
1990 	if (ret != 0)
1991 		uart_unregister_driver(&imx_reg);
1992 
1993 	return ret;
1994 }
1995 
1996 static void __exit imx_serial_exit(void)
1997 {
1998 	platform_driver_unregister(&serial_imx_driver);
1999 	uart_unregister_driver(&imx_reg);
2000 }
2001 
2002 module_init(imx_serial_init);
2003 module_exit(imx_serial_exit);
2004 
2005 MODULE_AUTHOR("Sascha Hauer");
2006 MODULE_DESCRIPTION("IMX generic serial port driver");
2007 MODULE_LICENSE("GPL");
2008 MODULE_ALIAS("platform:imx-uart");
2009